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CVE-2026-64286· NVD / CVE Program· CNA Linux

KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU

Noroxi assessment

Priority: Monitor (action score 32/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.17% (FIRST EPSS).
  • Someone with local access to the system can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 477145860dba4c30f0b4e36f02f4c5291c1c888b, 6bea2f8becdb20d34378493c3b77a9b9cf8c6cfa, d4f4d61715d1061ba83b88196a3605662be30750; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1.

Low priority for now. Upgrade to Linux Linux 477145860dba4c30f0b4e36f02f4c5291c1c888b, 6bea2f8becdb20d34378493c3b77a9b9cf8c6cfa, d4f4d61715d1061ba83b88196a3605662be30750; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU flush_hyp_vcpu() copies the host vCPU context into the hyp's private vCPU on every run. ctxt_to_vcpu() expects a guest context to have a NULL __hyp_running_vcpu, which is only ever set on the host context, so that it resolves the vCPU via container_of(). While this is generally the case, flush_hyp_vcpu() copies the context verbatim and does not enforce this, so a value provided by the host is dereferenced at EL2 (host -> EL2). Fix by clearing __hyp_running_vcpu after the copy.

HighCVSS 8.2 · v3.1—No exploit Fix available
Published
Jul 25, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 6th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
8.2
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-64286

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.2 and later · before 6.6.145
  • linux linux kernel6.7 and later · before 6.12.97
  • linux linux kernel6.13 and later · before 6.18.39
  • linux linux kernel6.19 and later · before 7.1.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.2affected
    • be66e67f175096f283c9d5614c4991fc9e7ed975 and later · before 477145860dba4c30f0b4e36f02f4c5291c1c888baffected · git
    • be66e67f175096f283c9d5614c4991fc9e7ed975 and later · before dfaef40d8a1533940fc1af788d70fce07362b4ceaffected · git
    • be66e67f175096f283c9d5614c4991fc9e7ed975 and later · before 6bea2f8becdb20d34378493c3b77a9b9cf8c6cfaaffected · git
    • be66e67f175096f283c9d5614c4991fc9e7ed975 and later · before d4f4d61715d1061ba83b88196a3605662be30750affected · git
    • be66e67f175096f283c9d5614c4991fc9e7ed975 and later · before e8042f6e1d7befb2fb6b10a75918642bcd0acf9aaffected · git
    • before 6.2not affected · semver
    • 6.6.145 and later · up to and including 6.6.*not affected · semver
    • 6.12.97 and later · up to and including 6.12.*not affected · semver
    • 6.18.39 and later · up to and including 6.18.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linux-6.12before 6.12.100-1~deb12u16.12.100-1~deb12u1
Debian:13linuxbefore 6.12.100-16.12.100-1
Debian:14linuxbefore 7.1.4-17.1.4-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now
  • CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV
    83Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-64283Jul 25, 2026 · KVM: guest_memfd: Treat memslot binding offset+size as unsigned values
    28Monitor
  • ← EarlierCVE-2026-64284Jul 25, 2026 · KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits
    28Monitor
  • Later →CVE-2026-64287Jul 25, 2026 · KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU
    32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux477145860dba4c30f0b4e36f02f4c5291c1c888bVendor (CNA)
Linux Linux6bea2f8becdb20d34378493c3b77a9b9cf8c6cfaVendor (CNA)
Linux Linuxd4f4d61715d1061ba83b88196a3605662be30750Vendor (CNA)
Linux Linuxdfaef40d8a1533940fc1af788d70fce07362b4ceVendor (CNA)
Linux Linuxe8042f6e1d7befb2fb6b10a75918642bcd0acf9aVendor (CNA)
azl3 kernel 6.6.144.1-1 on Azure Linux 3.06.6.145.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.12.100-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.100-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-4306781 days apartext4: handle wraparound when searching for blocks for indirect mapped blocks
    39Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • Administrator privileges are required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Local
Attack complexity
Low
Privileges required
High
User interaction
None
Scope
Changed
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-822 · Untrusted Pointer Dereference

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records